Need help defining pins

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Yalpsid
Posts: 12
Joined: January 12th, 2014, 8:29 pm

Need help defining pins

Post by Yalpsid » August 8th, 2014, 8:06 pm

The pins referenced in the .ucf, as p123 or something, are they the same as say pin 123 on the Mojo's headers and pin 123 on the Spartan6? thanks.

abalducci
Posts: 14
Joined: July 20th, 2014, 8:57 pm

Re: Need help defining pins

Post by abalducci » August 9th, 2014, 5:22 am

Your best reference for these types of questions is looking at the Mojo schematic, particularly pages 2-3:

http://embeddedmicro.com/media/wysiwyg/mojo/v3-sch.pdf

In this case p123 (L37N_0) looks like it is hooked up to one of the LEDs on the board.

SV1 and SV2 at the bottom of page 3 are your headers for the FPGA so referencing the connections to the four sides of the chip above U1B0, U1B1, ..., should give you your mapping to what pin outs are available.

Yalpsid
Posts: 12
Joined: January 12th, 2014, 8:29 pm

Re: Need help defining pins

Post by Yalpsid » August 14th, 2014, 3:09 pm

Looks like it does map accurately.

embmicro
Site Admin
Posts: 834
Joined: March 24th, 2013, 12:45 pm

Re: Need help defining pins

Post by embmicro » August 21st, 2014, 11:44 pm

The numbers on the Mojo's PCB are the same as the Spartan 6 pins. You can simply use Pxx where xx is the number on the PCB.

abalducci
Posts: 14
Joined: July 20th, 2014, 8:57 pm

Re: Need help defining pins

Post by abalducci » August 24th, 2014, 12:18 pm

Dear EM,

To be honest now I am slightly confused. My first glance at the schematic showed P123 heading to the resistor connected to the LED bed. However a re-examination also shows it heading to what is pin '50' (or as marked on the board), in the SV2 header... Does it some how serve dual roles, or am I misunderstanding?

embmicro
Site Admin
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Joined: March 24th, 2013, 12:45 pm

Re: Need help defining pins

Post by embmicro » September 11th, 2014, 2:53 pm

Sorry for not seeing this sooner. P123 goes to an LED. The '50' pin number on the header in the schematic doesn't correspond to anything (I believe P123 connects to '49'), you have to look at the silkscreen on the PCB (which should say 123).

The LED pins are broken out if you want to use them for something else.

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